Fan Advice

mgarl10024 · Post by **mgarl10024** » Fri Nov 20, 2009 5:10 am

Hi,

As documented here, I've recently bought a Silverstone GD04 and have been very pleased.

However, I am starting to notice the noise generated by the 3x120mm fans that come as standard (described by Silverstone as 1200rpm, 20dBA).
The noise isn't so much a mechanical whining sound, it's more of a constant "whoosh" of the air flowing through the grills.
I also have a Silverstone NT01-E passive cooler on my 5050e 45watt CPU, so I need to keep that happy.

As I see it, I have 4 options:
1) Replace the fans
I could buy 3 Noctua/Scythe or other fans. I'd have to be careful as these fans are drawing air in so would perhaps need to see which work best in this way? As I'm hearing a "whoosh" sound, I'm guessing that it is the airflow and so any silent fan would make the same noise?
2) Reverse the fans
Fans tend to make more noise when drawing air in. Perhaps if they were blowing out they would make less noise. Of course, this would destroy the positive air pressure design of the case. Would probably also need to do 3.
3) Remove the filters
Again a shame - the filters obviously keep the inside nice and dust free
4) Slow down the fans
Currently my favourite option. I'm hoping that a reduction from 12v to say 7/9volt may take the fans from 1200rpm to (a guessed) 900rpm and would give a significant drop in noise without harming airflow too significantly. However, as these fans are already running at 1200rpm and not, say, 2000rpm, perhaps they are already at the best part in the cooling/noise trade-off? Would also need to find out how to determine the start voltage of the fans, and what equipment would best achieve this - however I'll leave that until we know what we're doing!

Advice on the above, especially from GD04 owners or similar would be appreciated.

Thanks,

MG

Riffer · Post by **Riffer** » Fri Nov 20, 2009 6:05 am

Before you start spending money, try removing fans and see if you can maintain reasonable temperatures and reduce the noise to a tolerable level. Just because there is a fan mount doesn't mean you have to use it.

Post by **NeilBlanchard** » Fri Nov 20, 2009 6:48 am

Hi,

Yes, option #4 would be the place to start!

hybrid2d4x4 · Post by **hybrid2d4x4** » Fri Nov 20, 2009 1:13 pm

^ Agreed. 3 120mm fans @1000 RPM is way overkill for a low-power HTPC. They have that design to have overhead for those running a gaming-rig with hot vid cards. You should be able to get those fans down to <600 RPMs without compromising temperatures. That's where I'd start.

mgarl10024 · Post by **mgarl10024** » Tue Nov 24, 2009 4:14 am

Hi Riffer, NeilBlanchard and hybrid2d4x4,

Thank you for all your replies. I'm also relieved to learn that slowing things down is the way to go, rather than replacing all three fans.

In case you didn't know, the way the GD04 is set up is that each 120mm fan has a standard 3 pin fan connector (not PWM), and Silverstone supply you with a lead that splits one molex connector to the 3 fan connectors. I am happy with this - I wouldn't want to put the fans onto the motherboard jumpers as I'd imagine they need quite a bit of current so I would worry that they could cause damage - especially 3 on the one header.
I'm also not really interested in using the 7 Volt trick as I am not 100% sure that I understand what I'm doing and again wouldn't want to cause damage.

I've found RC56 and RC100 Resistors. I could imagine that I could buy 3 of them, one for each fan. Seems a shame having three resistors 'wasting' power but I can't find a resistor on a molex lead directly.

I've also found Zalman ZM-MC1 Fan Multi-Connector Cable. I could buy 2 of these (unless I can find a splitter), and run all 3 fans off the 5vt channel.

I've also found Zalman FANMATE 2 Variable Fan Speed Controller however this seems to be for just 2 fans. Would again be a shame to have two of these, so would probably want a splitter. I do like the idea that it's variable. Would it be happy taking 3 fans?
Anything with more than 3 seems to take up a 5.25" bay and have dials etc. and I don't want that in a HTPC.

Finally, with respect to start-up voltages, without testing, how would I know that my fans would start ok and work at 5vt? Leads me to think that the fanmate could be the winner as if it's variable I can adjust it as required.

Suggestions very welcome,

MG

teejay · Post by **teejay** » Tue Nov 24, 2009 5:54 am

Zalman Fanmates are great little products. They control 1 fan each (it has a male and a female connector). A motherboard fan header is usually well capable of running a 120mm fan, so you could simply buy 3 and connect them to your motherboard. As an alternative, you could link the Fanmates to your current splitter cable.

This gives you a wide variety of options in terms of speed versus temperature, a lot better than the low/high character of the ZM-MC1 cable. A lot of slower 120mm fans do not run very well on 5V and need a bit more voltage; the Fanmates can easily provide this. Also, you can run the little boxes out the back for easy adjustment if your machine is running too hot.

The benefit of using your mainboard headers is that you have the option to control the fan speeds through software (e.g., Speedfan) if your motherboard allows this.

EDTI: psellign

hybrid2d4x4 · Post by **hybrid2d4x4** » Wed Nov 25, 2009 8:13 pm

I'd first try running the stock fans at 5V since it costs you nothing. I'm guessing that the "lead that splits one molex connector to the 3 fan connectors" only uses 2 of the molex pins. You can probably swap around the pins inside the molex connector to use the 5V line instead of the 12. It takes no more than 5 mins and is reversible in case the fans don't start at 5V reliably.
Failing that, I vote for one Fanmate2 to control all 3 fans with some ghetto wire-splicing/improvised adapter.

Riffer · Post by **Riffer** » Thu Nov 26, 2009 6:54 am

After you slow the fans down, remember to do a cold boot to make sure they are all starting properly.

mgarl10024 · Post by **mgarl10024** » Sat Nov 28, 2009 4:39 am

Hi teejay, hybrid2d4x4 and Riffer,

Thank you very much for your responses and all your great advice.

I did as advised by hybrid2d4x4 and found an old molex-molex connector and swapped round the 12v and 5v cables allowing all 3 fans to run at 5volt. As recommended by Riffer, I made sure to try them from a cold boot and as feared they just twiched. They would run if started at 12v and then I quickly swapped the cables - and annoying at 5v they sounded really *silent* and yet still produced quite a breeze. This encourages me that slowing them down will give the silence I'm after but will not disgrade cooling too much. This advice has also saved me buying the 5v resistors or fan multi-connector cable and being disappointed so thanks!

My next "experiment" will be to try using a fanmate2 that someone has kindly given me. I'll run it from a molex lead using the Silverstone molex-3pin fan lead as I don't want the fans running off the motherboard. Then, using 2 of these splitters I can power all three fans through the one fanmate2.

The concern here for me is overloading the fanmate2, and the problem I've got is not being able to find any stats about the fans. I know that the fanmate2 will take upto 6watts, however Silverstone just say "2 x 120mm intake fans, 1200rpm, 20dBA", there's nothing obviously written on them and none of their products I've found have the "golfball" texture fans.
The nearest of their range I've found is the FN121 which is the sameish speed and says Max 2.76watts, so if I were running them at a much lower speed (and wattage), I reckon the fanmate2 could take all 3 at once without dying. What do people think?

Thanks for all your help - really appreciated.

MG

hybrid2d4x4 · Post by **hybrid2d4x4** » Sat Nov 28, 2009 6:04 pm

I've been running 2 120mm S-Flex fans on a single Fanmate2 for over 1.5 years in my HTPC with no apparent issues so far. I'd say give it a try!

mgarl10024 · Post by **mgarl10024** » Mon Nov 30, 2009 3:35 am

Hi all,

All installed and working.

As indiciated below, I installed a FanMate2 with 2 Cable Splitters.

I stopped the fans completely, then with the fanmate at the slowest setting kept increasing the power until they started on their own. Then, to ensure they would start ok from cold, I started/stopped them a few times by disconnecting/reconnecting the power.

At this speed (the slowest I could get away with), the fans were *silent*, however I did start to have a few heat issues when the CPU was under load - nothing noticable however the CPU did run unacceptably warm (80degrees at one point) with the Silverstone NT01-E passive cooler.

I've tweaked the fans up a bit higher now, and the fans are audible but only just - a massive improvement. CPU load temps are around 60, idle around 25. To me, this feels like a fair compromise - I wouldn't want to go any slower/hotter or any quicker/louder.

Thanks to everyone who gave advice - it's really made a huge difference.

MG